Grinding wheel



April 22, 1952 J, DOERMANN GRINDING WHEEL 2 SHEETS-SHEET 1 Filed Sept. 12, 1949 April 22, 1952 A. J. DOERMANN GRINDING WHEEL 2 SHEETS-SHEET 2 Filed Sept. 12, 1949 Patented Apr. 22, 1952 UNITED GRINDING WHEEL Albert J. Doermann, Chicago, 111., assignor to Titan Abrasives Company, a corporation of Illinois Application September 12, 1949, Serial No. 115,266

9 Claims. 1

This invention relates to a grinding or abrasive wheel, and relates particularly to such a wheel comprising a plurality of adjacent grinding disclike elements adapted to be locked together for making the completed wheel.

One of the features of this invention is to pro' vide a rotatable grinding wheel comprising a plurality of adjacent grinding disc-like elements each having a tongue on one side engaging a groove on the adjacent side of the next element with at least one of the cooperating edges of a tongue and groove being at an angle to a radius of the wheel to aid in restraining a broken section from being thrown outwardly by centrifugal force when the wheel is rotated; another feature of the invention is to provide such a wheel wherein both side edges of the tongue and groove are at an angle to each other; a further feature of the invention is to provide such a wheel having a plurality of annular disc-like elements wherein the cooperating opposite sides of the tongue and groove are inclined toward'each other from inner portions of the elements to the peripheries thereof; yet another feature of the invention is the provision of a grinding wheel comprising a plurality of adjacent grinding disc of adjacent tongues and corresponding grooves with .each pair of tongues and grooves being in- ,clined" toward each other from the inner ends thereof to'the periphery of the wheel; and anotherfeature of the invention is to provide a grinding wheel comprising adjacent disc-like elements with at least one endv element being of a grindin character different from that of at least one of the other elements. Other features and advantages of the invention will become apparent in the following descriptions of two em' bodim'e'ntsof the invention taken in conjunction with the accompanying drawings. "Of the drawings'.

Fig. 1 is an end elevation of a grinding wheel embodying the invention.

Fig. 2 is a side elevation of the wheel of Fig. 1. Fig. 3 is a sectional view taken substantially along line 33 of Fig. 2.

Fig. 4 is a fragmentary sectional view taken substantially along line 4- -4.ofFig. 3.

" Fig.5 is an end elevation partly in section of a grinding wheel illustrating a second embodiment of the invention.

Fig. 6 is a side elevation of the grinding wheel of Fig. 5.

The grinding wheel of this invention is particularly designed for grinding where the wheel is positioned adjacent tobut-spaced from either a second grinding 'wheel or an idler wheel. The metal elements to be ground are ordinarilybf substantially circular cross section and are 'fed between the grinding wheel and the second grinding wheel or the idler wheel at one end thereof and progress along the face of the wheel during the grindin operation. The ground elements are eventually ejected from the other end of the wheel. The timing is such that the grinding is ordinarily completed by the time these elements are ejected.

The grinding wheels ordinarily comprise a hard binder such as hard rubberyvitreo'us clays, or a resinoid binder such as a phenolic condensation product with an aldehyde, having incorporated therein particles of a grinding material such as aluminum oxide. As the grinding wheels are ordinarily of relativelygreat thickness when of one piece construction, it is quite diflicult cure the resinoid binder uniformly throughout the wheel. The abrasive, being a refractory material, also interferes with proper heat transfer to the center of the wheel during the curing steps. As a result the center of an ordinary resinoid wheel often remains at least partially uncured or soft. These disadvantages are avoided in the present grinding wheel as the wheel is made up of relatively thin grinding diselike elements. These are made separately and are provided with interlocking tongues and grooves so arranged that if a piece of one element breaks, the broken element will be restrained against being thrown outwardly by centrifugal force. z The multi-layer grinding wheel of this invention also permits making the various disc-like elements of different grinding characteristics, if

desired. Thus, the end section where the metal elements to be ground, such as automobile valves, are introduced can be made harder as this end disc-like element is subjected to the greatest wear. This end disc-like element can not only be made of a different formula, but may also be compacted to a greater density during the manufacturing operationto provide an extremely hard leading edge for the wheel. The end disclike element can also be given a different grinding character by providing a 'difierent curing time and temperature than thoseof the other elements. Similarly, if desired, the beginning element or elements may .be made very coarse so that rough grinding may be accomplished easily and rapidly and one or more of. the succeeding disc-like elements may be vmade with finer abrasive. so thatthe metal element to be ground may be roughed and finished in a single pass across the face of the grinding wheel. With a standard grinding wheel it is not too difflcult to make one end harder than the remainder of ..cularsteel holding plates I6 and E1. trated here, the assembly of grinding disc-like the wheel. but because the entire wheel'must be compressed'at one time during the manufacturing operation, the grain structure and the density cannot be varied substantially.

In the ordinary grinding wheel constructed according to this invention, it is sometimes desirable to provide a slight clearance-between adjacent grinding elements so as to allow the grindings to escape. In the ordinary wheel of this invention the areas at the joints wear away fairly rapidly so as to provide automatically for this clearance. However, when the work being performed is of such a nature that no clearance J's-desired, a'cement or bonding material may be chosen suchthat layers of extremely hard material may be provided (upon curing of the bond) between adjacent grinding elements, thereby greatly increasing. the'life of the wheel.

gin-the present application the term grinding disc-dike element is used to include both the grinding element and any intermediate layer of 'hard' material "which may exist between the grinding elements as a result of the selection 01 a resinoid bonding material having this characteristic when cured.

adhesive present in restraining a broken sec tion of either element from being thrown outwardly by centrifugal force when the wheel is rotated. Such a tongue and groove arrangement may beprovided in many different forms 01' designs,

Two arrangements are illustrated in the accompanying drawings.

In the embodiment shown in Figs. lto 4, in-

elusive, the grinding Wheel comprises a plurality (if-adjacent grinding disc-dike elements 10, H,

I i2, I3, I4- and I5. These elements are of annular shape, as shown in Figs. 3 and 4. While these elements would normally be cemented together "before being shipped, primarily as a matter of convenience in handling, they may also be mereiy-mechanically held between substantially cir- As illuselements is held tightly clamped by spaced studs crbolts -IB extending between the plates and .located within the center openings of the disc- :like elements at points just within the inner peripherythereofi This may be independent of,

or supplemental to, the locking provided by a cement bond, andit is to be understood that When I speak of the disc-like elements as being "locked together I intend this term to cover either a cement bonding or a mechanical locking, or. both. The holding plates I6 and I1 also provides. mounting for fixing the wheel on a rotatable shaft I9.

As can be seen in the drawings, the grinding V disc-like elements II to I4, inclusive, are subedges I of the tongue I2a are inclined inwardly toward each other from the inner to the outer periphery of the element. As will be noted, each of the side edges We is also inclined at an angle to a. radius of the grinding Wheel.

- The grinding disc-like element I2 is also provided on the side opposite the tongue In with a groove I2b for receiving the tongue of the adjacent element- I I. The grinding disc-like element I3 is also provided with a plurality of tongues 13a engaging grooves in the next disc-like ele ment It. As can be seen in Figs. 2 and 3, the succeeding tongues and grooves of the diiierent grinding disc-like elements are preferably out of line with each other so that the wheel will notbe unduly weakened in any singlesection. Thus, as shown in Fig. 2, the tongue and groove IEa and I319 are spaced circumierentially from the groove I21) and the corresponding tongue, and from the tongue I3a and thecorresponding groove.

' Theouter side surface of each outer grinding disc' like element l0 and I5 is preferably made planar, as shown in the drawings, so that the grinding wheel will have a cylindrical appearance. Because of this the end elements it) and I5 are different from the intermediate elements II to I4 in that the first end element I0 is provided with tongues on the inner side thereof, while the other element I5 is provided with grooves on the inner side thereof. However, the areas on the end element I0 between the described tongues serve as grooves to aid in locking the element in position, while the spaces on the other end element I5 between the described grooves serve as tongues.

In the embodiment shown in Figs. 5 and 6, the grinding wheel comprises grinding disc-like elements'IIo, Iii, H2, H3, II4 and H5, with the wheel retained between holding plates I6 and I1. Connecting studs or bolts i8 extend between the plates and the wheel assembly is mounted on a rotatable shaft I9. Each grinding disc-like element I II] to I I4 is provided with a pair oftongues as shown at IIIla engaging similar grooyes'as shown in NH). The tongues II Ila are arranged in pairs and the tongues of each pair are arranged adjacent each other. The pairs of tongues are substantially equally spaced around the grinding wheel, as shown in Fig. 5. Each tongue I lflahas substantially parallel side edges and each tongue and groove is inclined with respect to a radius of the grinding wheel. The tongues and grooves. of each pair are inclined toward each other from the inner periphery of the disc-like elements to the outer periphery thereof. These tongues and grooves aid in restraining a broken section of either element from being thrown outwardly by centrifugal force when thev wheel isrotate'd.

In both embodiments of the invention the adjacent disc-like elements are preferably cemented together as indicated at 20 in Fig. 4 and I20 in Fig. 6 to make a grinding wheel. The Wheel may then be mounted between the holding plates by the user.

One type of commercial wheel made according to the invention would employ disc elements having an exterior diameter of 20 inches, an interior diameter of 12 inches, and would use six disc elements each about one inch thick. The plates I6 and I1 would each be of about 16 inches diameter.

Having described my invention as relatedto the embodiments shown in the accompanying drawings, it is my intention that the invention be not limited by any of the details of description unless otherwise specified, but rather be construed broadly within its spirit and scope as set out in the accompanying claims.

I claim:

1. A grinding wheel, comprising: a plurality of adjacent grinding disc-like elements each having a plurality of tongues on one side each engaging a groove on the adjacent side of the next element, one of the cooperating side edges of a tongue and groove being inclined toward an ad-- jacent other of said cooperating side edges from a point nearer the center of the wheel toward the periphery thereof to aid in restraining a broken section of either element that includes at least part of at least one of a tongue and a groove from being thrown outwardly by centrifugal force when said wheel is rotated.

2. A grinding wheel, comprising: a plurality of adjacent grinding disc-like elements each having a plurality of tongues on one side each engaging a groove on the adjacent side of the next element, each of a pair of cooperating side edges of a tongue and groove being inclined toward the other from a point nearer the center of the wheel toward the periphery thereof to aid in restraining a broken section of either element that includes at least part of at least one of a tongue and a groove from being thrown outwardly by centrifugal force when said wheel is rotated.

3. A grinding wheel, comprising: a plurality of adjacent grinding disc-like elements with at least one element having a pair of adjacent tongues engaging similar grooves in a next element, the adjacent side edges of one of said pair of tongues and grooves being inclined toward the other from a point nearer the center of the wheel toward the periphery thereof to aid in restraining a broken section of either element that includes at least part of at least one of a tongue and a groove from being thrown outwardly by centrifugal force when said wheel is rotated.

4. A grinding wheel, comprising: a plurality of adjacent annular grinding disc-like elements each having a plurality of tongues on one side each extending from the inner edge of the element to the periphery thereof and each tongue engaging a groove on the adjacent side of the next element, the cooperating side edges of a tongue and groove being inclined toward an adjacent other of said cooperating side edges so that said side edges are inclined toward each other from said inner edge to the periphery thereof to aid in restraining a broken section of either element that includes at least part of at least one of a tongue and a groove from being thrown outwardly by centrifugal force when said wheel is rotated.

5. A grinding wheel, comprising: a plurality of adjacent annular grinding disc-like elements each having a plurality of tongues on one side each extending from the inner edge of the element to the periphery thereof and each tongue engaging a groove on the adjacent side of the next element, each of a pair of cooperating side edges of a tongue or groove being inclined toward the other from said inner edge to the periphery thereof to aid in restraining a broken section of either element that includes at least part of at least one of a tongue and a groove from being thrown outwardly by centrifugal force when said wheel is rotated.

6. A grinding wheel, comprising: a plurality of adjacent annular grinding disc-like elements with at least one element having a pair of adjacent tongues extending from the inner edge of the element to the periphery thereof and engaging similar grooves in a next element, the adjacent side edges of one of said pair of tongues or grooves being inclined toward the other from said .inner edge to the periphery thereof to aid in restraining a broken section of either element that includes at least part of at least one of a tongue and a groove from being thrown outwardly by centrifugal force when said wheel is rotated.

7. A grinding wheel, comprising: a plurality of adjacent annular grinding disc-like elements each having a plurality of tongues on one side each extending from the inner edge of the element to the periphery thereof and each tongue engaging a groove on the adjacent side of the next element, the cooperating side edges of a tongue or groove being inclined toward an adjacent other of said cooperating side edges from said inner edge to the periphery thereof to aid in restraining a broken section of either element that includes at least part of at least one of a tongue and a groove from being thrown outwardly by centrifugal force when said wheel is rotated, at least one end element of said wheel having grinding characteristics different from those of at least one other element.

8. A grinding wheel, comprising: :a plurality of adjacent annular grinding disc-like elements each having a plurality of tongues on one side each extending from the inner edge of the element to the periphery thereof and each tongue engaging a groove on the adjacent side of the next element, each of a pair of cooperating side edges of a tongue and groove being inclined toward the other from said inner edge to the periphery thereof to aid in restraining a broken section of either element that includes at least part of at least one of a tongue and a groove from being thrown outwardly by centrifugal force when said wheel is rotated, at least one end element of said wheel having grinding characteristics different from those of at least one other element.

9. A grinding wheel, comprising: a plurality of adjacent annular grinding disc-like elements with at least one element having a pair of adjacent tongues extending from the inner edge of the element to the periphery thereof and engaging similar grooves in a next element, the adjacent side edges of one of said pair of tongues or grooves being inclined toward the other from said inner edge to the periphery thereof to aid in restraining a broken section of either element that includes at least part of at least one of a tongue and a groove from being thrown outwardly by centrifugal force when said wheel is rotated, at least one end element of said wheel having grinding characteristics different from those of at least one other element.

ALBERT J. DOERMANN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 229,513 Allen July 6, 1880 872,321 Allen et a1. Dec. 3, 1907 1,912,069 Doermann May 30, 1933 FOREIGN PATENTS Number Country Date 319,200 Great Britain Sept. 16, 1929 

